Improved electro-magnetic fire-alarm apparatus



PATENTED JAN. 11, 1859.

M. G. FARMEB ELECTROMAGNETIC FIREALARM APPARATUS.

Witness es BQEZZW THE "cums PEYERS co.. mom-urns" WASHYNUTOrLD. c.

UNITED STATES PATENT OFFICE.

i M. G. 'FARMER, OF SALEM, MASS ASSIGNORTO F. CHAITNING,

IM PROVED ELECTED-:MAGNE'I'IC 'Fl RE-ALARM APPARATUS.

Specification forming part of Letters Patent No. 22,653, dated January 11, 1859.

To all T'wlzom it may concern:

- Be it known that'I, MOSES G. FARMER, of

Salem, in the county of Essex and State-of Massachusetts, have iuventeda new and usefni Apparatus or Mechanism which I have called a Telegraphic Fire-Alarm Signal-Box,.

strument could, by means of such i-nstrument--- an electromagnetic circuit, and: a suitably-arranged apparatus at theceutral stationtelegraph thereto the exact locality of a fire. In order, however, that prompt notice may be given to the central station of any fire that may take place, -it is necessarythat the city be divided into a great number of districts or sub-districts, and that there he a telegraphingonsignaling station in each of such sub-districts; but it'will, manifestly, not he-practicable tohave a telegraphic operator constantly upon the alert at each of the. stations of a large city, and the object of myinvention is to enable any person of ordinary intelligence to sig'n'alizc from any station the occurrence of a lire near that station; and myinventionconsists of an apparatus placed within the electromagneticcircuit consisting of a circuit-wheel having certain pins or projections upon itspe riph'ery, in connection with a key so arranged that asthe circuit wheel is rcvolved'the circuit shall be "closed and; broken, and thus a definite signal shall'always be'scnt to the ecu-- tral station corresponding to the station from which the alarm is given, the circuit-wheel to be furnished with means for turnmgihwhether thisbe a crank upon its shaft by which it may be turned by hand, or by suitable connections with a spring, which maybe wound up temporarily a sutiicient distance to turn the circuitwheel. In the latter case the motions of the circhit-wheel should be regulated by a fly or otherwise.

The mechanism which I have contrived, and

- which I will nowproceed to describqconsists,

first, .of a circuit-wheel and the means of actuating it and regulating its motion; secondly, -of the means by which the signal indicated upon the circuit-wheel is transmitted to the central station.

In the accompanying drawings the circuitwheel is indicated at to. Its shaft carries a piniontnot seen in the drawings) which engages :with'a wheel,b, upon the shaft of which is a pinion which engages with a wheel, c,runnin g loosely upon the shaft d. The latter is so, connected with this shaft by means of a ratchet-wheel,f,i1nd a elicit, e, that when the shaft' (1 is revolved by moving its handle B in the direction of the'arrow I the shaft, together with the ratchet-wheel attached to it, shall move independently of the wheel c and its click; but when the handle B is moved in a direction contrary to its arrow the ratchet wheelf, engaging with the click, shall drive the wheel 0 in the direction of the arrow 2, and, through the connections already explained,the circuit-wheel a in the direction of its arrow3.

The wheel 0 is prevented from moving in a direction contrary to the arrow2 by the detent g; The shaft d carries a spring, 0, the outer end of which is attached to the frame-work A, and which is so arranged that as the'handle B is moved in the direction of its arrow, into the position indicated in red, the spring is wound up, and as itrccoils it returnsthe handle B to its position at rest against the plate I), and at the same time revolves the wheel 0 and the circuit-wheel in the direction of their arrows, the motion of the circuit-wheel being regnlatedas follows: The shaftot' the circuitwheel has a wheel, h, which engages with a pinion, 2', upon the shaft on of a. fan the. vanes of. which are adjustable so as to retard more or less thevelocity of the circuit wheel. The circuit-wires enter theboxand proceed the oneto thescrew-cnp F, thence to the electromagnet G, thence to the metallic plate D, thence to the insulated metallic piece It, thence by the key H to the metallic framcwork A, thence by the wire land screw-cup I out of the box.

The piece It being, insulated, if the key H- be ra-iscd into contact with its anvil p the circuit will be broken; but when the mechanism is at rest the key H is retained in contact with the rangement in each box, the circuit-wheel of each station having its specific number or arrangement of teeth. These teeth, as the cir cuit-whcel revolves, strike against a tooth, s, pro ecting from the underside of the key H, by wluchmeans this keylis raised from oft the metallic piece k and dropped upon it again,

similar to that above described through every signal-box in the circuit; and it is obvious that if the current be interrupted in any one of the boxes between the piece 7.: and the key H the circuit will be broken at this point, and should be complete without passing through the piece k and key H in all the boxes of the circuit, ex-

cept in the one from which the signal is bein g sent, the following device is employed:

, Mis'jt metallic spring, which is in electric connection with the plate I). N is a springin similar connection with the frame-work A.

The springs are so arranged that when the door of the box is open they do not come in contact; but when the door is closed it strikes against the pin -10, projecting from the spring 1N, and presses the latter against the spring M,

there, being suflicient space between the latter and the wooden shelf It to permit the spring M to yield as the door closes.

The electric current has two ways by which it can pass through all those boxes which are closed-the onealread y indicated through the piece K and the key H, and the other from the magnet G to the plate 1), thence, by the springs M and N, to the fr'ameA, and by the .wire 2, as before, out of the box. \Vhen, however, the door of the box is opened the spring N leaves the spring M and the current has but one course, as before indicated, from the piece It to the key'H.

Operation: The above described signals boxes are placedatthe pelice statlonmengmehouses, or even at the corners of the streets, there being one signal-box for each sub-district or station into which the city is divided, the circuit-wheel of each signal-box having its own peculiar arrangement of pins or teeth upon its periphery, as before described, that itmay be instantly known at the central station from which sub-district the alarm, proceeds. 0n the'occurrence of a fire in any part of the city a fireman, policeman, or any'other' person intrusted witha station-box key, re-

pairs to the nearest box and opens the door. The contact between the springs N and M of this box being thus broken, the electric current passes through this box by way of the piece It and key H. By means of the knob B the handle upon the shaft d is revolved over into the position seen in red, by which the spring 0 is wound up suificiently togive the circuit-wheel thirty or forty turns, more or'less'. The knob B is then released, and as the spring runs down the handle returnsto its original position of rest upon the plate D. The circhit-wheel thus revolved transmits the alarm to the central station, from which the general alarm is given upon the fire-bells of the city. The operator at the central station now telegraphs back to the station that'the alarm was received, which is indicated by the blows of the hammer 0 upon the box or bell. Tins same hammer is also employed to signalize to all the signal-boxes of the city the number of the sub-district or station from whence the alarm was received. The key H may be manipulated'byha11d,and thus any message may be transmitted from the different station-boxes to the central station. n,

-'In lieu of employing the motive power of aspring to actuate the circuit-wheel the crank may be placed directly upon the shaft of this wheel, which may then be turned moderately by hand a sufficient number of times to trans- \nit the alarm as before. In such case the fan for rcgulatin g the motion of the circuit-wheel would also be dispensed with. I

\Vhat I claim as my, invention, and desire to secure by Letters Patent, is-- 1. The circuit-wheel a and the crank or han-' dl'e bywhich it is actuated, in combination with the key Hand the electromagnetic circuit, operating in the manner substantiailyas set forth, to send a definite signal from a subdistrict to the central station.

2. The method of completing the circuit when the door of the signal-box .is -closed, through the springs M and N, asset forth, for thepurpose described.

MOSES G. FARMER.

Witnesses:

Taos. lit-Boson, P. E. TESOHEMACHER. 

